This invention relates to an apparatus for assisting the advancement of a tubular work string. More particularly, but not by way of limitation, this invention relates to an apparatus and method for advancing a tubular work string in a highly deviated or horizontal concentric tubular member.
As those of ordinary skill in the art will recognize, tubular members are used to transport liquids and gases from a first processing facility to a second processing facility. Also, tubular members are used to convey hydrocarbons from subterranean reservoirs to surface production facilities. The hydrocarbons are then transported from the production facilities to processing plants, such as an oil and gas refinery.
In each instance of conveyance, the tubular member may become coated with deposits that impede the transportation. The deposits may cause and/or accelerate corrosion. Also, it is sometimes necessary to perform certain types of remedial work to the inner diameters of the tubular members. For instance, in the case were the tubular member is a well bore completed to a subterranean reservoir, down hole tools may need to be set within the well bore, or alternatively, down hole tools may need to be retrieved. Regardless of the specific application, a concentric tubular member can be run in order to perform the desired work.
One means for accomplishing these task includes use of a coiled tubing string. The coiled tubing string is inserted into the inner diameter of the tubular member. The coiled tubing string will have the necessary down hole assembly in order to perform the desired task. For instance, the coiled tubing may have a wash tool adapted on one end, with the wash tool configured to deliver a cleaning solution to the inner diameter of the tubular walls. Another example is the coiled tubing may have a tool selectively attached thereto, with the tool being designed to be set into the inner diameter of the tubular member. Examples of tools used in this instance includes packers, plugs, screens, liners, etc. The examples herein given are illustrative and not exhaustive.
A problem encountered during operation is that the concentrically placed work string will lie on and rub the inner diameter portion of the tubular string. This causes problems in the advancement of the tubular work string as well as adding to the potential wear and tear which in turn could lead to failure of the work string. Sometimes, the problem of friction becomes so severe that it is not possible to retrieve the work string.
Operators have devised certain devices to aid in the advancement of the work strings. For instance, there has been developed a centralizer that works to center and stabilize the work string within the inner diameter of the tubular member. However, there is need for an apparatus that will centralize the work string and also reduce the friction between the work string and the inner diameter wall so that advancement is accelerated. Also, objects within the tubular member may impede advancement of the work string. Thus, there is a need for an apparatus that will deflect these objects which in turn will allow for proper advancement of the work string.